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4 Sheets-Sheet 1. H. APHARVE Y- Machine for Rolling Threads ofSbrew's orBolts.

No. 223,730. Patented ranqzo, 1880.

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4 sheets -sflet H. A HAQRVEY. Machine for Rolling Threads of Screw-s orBolts.

- No. 223,730. Patented Jan. 20, 1880..

Rmamss NPEYERS, PHOYO-UTHOGRIPNER. WASHINGTON. 0 CV 4 Sheets-Sheet, 3.

. H. A. HARVEY. Machine for RollingThreads of Screws OLBOPBS/V PatentedJan. 20, -1880.

EQ W N. PETERS, FNOTOUTNO GRAP 4 sums-sheep 4. H. A. HARV EY. Machinefor RollingThreads of Screws or Bolts.

No. 223,730. Pat ented Jan. 20, 1880.

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UNITED STATES PATENT OFFICE.

HAYWARD A. HARVEY, OF ORANGE, NEW JERSEY.

MACHINE FO'R ROLLING THREADS OF SCREWS-OR BOLT S.

SPECIFICATION forming part of Letters Patent No. 223,730, dated January20, 1880;

' Application filed October 15, 1879.

To all whom it may concern Be it .known that I, HAYWARD A. HARVEY, ofOrange, New Jersey, have invented certain Improvements in Machines forRolling the Threads of Screws or Bolts, of which the following is aspecification.

My improvements relate to apparatus for forming the threads of screws orbolts by the combined action of a curved stationary die and acylindrical rotating die upon a blank introduced between the dies androlled along the face of the stationary die by the friction of therotating die.

In dies of this kind the-screw-threads have been heretofore impressedupon the body of the blank by parallel ridges of metal formed upon thefaces of the dies at the proper angle of inclination with the plane ofmotion of the rolling-die.

My invention consists, first, in transversely notching at intervals theparallel ridges on thefaces of the dies, so that they may presentaseries of sharp points or corners which will have a cutting action uponthe blank, such removal of a portion of the metal from the blank beingthe result of the differential action upon the blank of the notchededges and the sides and bottoms of the grooves formed in theworking-faces of the dies, and thereby operate to effectthe formation ofthe thread partly by displacing -or upsetting the metal and partly bythe actual removal of a portion of themetal from the blank.

The second part of the invention consists in the combination, with eachother, of two or more pairs of dies, the first pair of dies being soorganized as to form a comparatively shallowgroove in the path of thethread around the shank of the blank, and the next pair of dies being soorganized as to make such groove deeper, either to the extent offinishing the thread or of partially finishing it, preparatory tosubjecting the blank to the action of a third pair of dies, and so onuntil a thread of the desired depth is formed.

In carrying out myinvention I may arrange successive pairs of dies inclose proximity and feed the blank directly from onepair of dies to thenext pair, or I may introduce between the pairs of dies a rotatingtransfer-wheel, acting in conjunction with a concave guidewall, forcarrying the blank fromthe pair of dies in which it is first operatedupon to the pair of dies which next act upon it. In either event thecombination with each other of the successive pairs of dies, or of thesuccessive pairs of dies andthe intermediate transfer mechanism, is suchthat the blank, after having been operated upon by one pair of dies, isso presented that the ridges in the next fol: lowing pair of dies willengage the spiral groovealready formed upon the periphery of the blank.v

The accompanying drawings, which illustrate a machine embodying myinvention, and

also embodying several other inventions which I am about to make thesubject of a separate application for a patent,are as follows: Figure 1is a front elevation, showingthe ex posed portions of the faces of tworolling-dies mounted in suitable bearings and geared to a central shaftcarrying the intermediate transfer-wheel, the two systems of dies andthe transfer-wheel being arranged in the same plane. Fig. 2 is an endelevation of themachine, affording a side view of a hopper for carryinga mass of blanks, and ways in which I the blanks are conducted from thehopper to the tube, from which they are permitted to drop into a recessat the end of the stationary die. Fig. 3 is a transverse section throughthe machine on the line as a: on Fig. 1', exhibit ing in section theshafting upon which the dies and the transfer-wheel are mounted, andalso showing an. oscillating pusher, which pushes the blanks sidewisesuccessively into the space between the-first pair of dies. Fig. 4 is aview, in detail, of the pusher and the oscillating arm upon which it ismounted, showing I the tripping-pawl which is affixed to the oscillatingarm of theylever, and which, after having been caught by a pin ontheface of I the die and moved a prescribed distance, is

tripped from the pin, and thereby permits the oscillating arm to springback to its normal position. Fig. 5 is a section,on an enlarged scale,through the line y 3 on Fig. 3, showing the shape of the working-facesof the first pair of dies. Fig. 6 is a similar section through the line3 g on Fig. 3, sbewing the shape of the working-faces of the second pairof dies. Fig. 7 is a section through the linezz on Fig.

3, showing a milling-wheel for cutting the cone-point upon a screw whichis being operated upon by the second pair of dies. Fig.

8 is a view, on a still larger scale, of the working-face of one of thedies, showing the transverse notching of the parallel ridges formed inthe face thereof. Fig. 9 is a transverse vertical section through thecentral portion of the hopper and through the lifter, by means of whichthe blanks in the hopper are caught by the head and lifted so that theyfall by. gravity into the ways which conduct them to the check.

The various parts of themachine are Inountwith the curved stationary dieI), and the transfer-Wheel 0 acts in conjunction with the curvedguide-wall 0, while the secondary die cl acts in conjunction with thecurved stationary die d.

The shaft B is provided on its lower end witha cam or eccentric, B,which imparts a reciprocating motion to the cam-bar B The cam-bar B isprovided at the end with a transverse pin, B which is inserted in theforked arm of the bell-crank lever B By reason of this connection thebell-crank lever is caused to oscillate by the movement of the cam-bar Band this oscillating motion is transmitted, by means of the pitman B tothe lifter E.

The lifter is composed of two parallel plates, 0 e, of segmental form,which are arranged at the desired distance from each other, and arefastened together and pivoted to the upper end of the ways 0. The twoparallel plates of the lifter are in line, respectively, with the twoparallel plates of the ways, and reciprocate in a vertical path in thecenter of the hopper E. The bottom of this hopper is slotted to allowthe movement of the lifter, and the range of movement of the lifter issuch that the upper edges of the two parallel plates 0 6 drop from theposition in which they are shown in Fig. 2 to a point slightly below themouth of the opening in the bottom of the hopper, as

shown in Fig. 9.

Blanks are thrown indiscriminately into the hopper, which has, it willbe seen, converging side walls. point, the blanks are permitted to dropinto the opening in the bottom of the hopper, and are caught between theparallel plates of the lifter, and when the lifter rises hang therein bytheir heads, and slide therefrom by gravity into the ways.

is shown in Fig. 3.

When the lifter falls to its lowest Hoppers and lifters of thischaracter are well known.

At the bottom of the ways there is the usual reciprocating gate orcheck, F, which is thrust outward by the cam f on the shaft B, and isreturned to its normal position, as the cam continues its rotation, bythe spring f. The gate or check F, in its reciprocating movement, cutsoff a blank from the lower end of the row of blanks hung by the heads inthe ways, and permits it to drop through the short tube or guide f(indicated in dotted lines on Figs. 1 and 2) into the space between theperiphery of the rolling-die b and the guide-wall b at the end of the.stationary die b.

The blank is held in a vertical position by the guidewall b the concaveend of the pusher g, and the spring g, which is affixed to the pusherand partially embraces the body of the blank.

The pusher g is affixed to a stud on the end of the oscillating arm H,projecting radially from a loose hub, h, on the shaft B, immediatelybeneath the rotating die I). Loosely hun g on the stud is a tripper, H,in the form of a bell-crank lever, one of the arms of which pointstoward the hub H, while the other stands at about a right angle with thefirst,

A pin, h, projecting radially from the hub h, is connected to the end ofa spiral spring, [1/2, the opposite end of which is secured to the frameof the machine, and the pull of this spring tends to hold theoscillating arm H in the position in which it The under side of therotating die I) is provided with a pin, H which, as the die rotates,strikes against the inwardly-turned arm of the tripper H- and carriesthe oscillating arm H around until the roller on the end of the outerarm of the tripper has traveled to the end of the concentric part of theguide H at which point the tripper is free to turn on its axis, andhence releases itself from the pin H while in obedience to the action ofthe spiral spring h the arm H moves back to its normal position.

In the act of moving forward, however, the pusher g has delivered theblank caught in the recess G so far into the space between the rotatingand stationary dies that the blank is caught by friction androlledforward around the face of the stationary die.

The dies b and b, by a continued graving and compressing action upon theperiphery of the blank, produce a shallow groove upon it in a spiralpath corresponding to the path of the screw-thread.

Having traveled to the opposite end of the stationary die I), the blankis delivered to and caught by the transfer-wheel c, which rolls itaround the guide-wall c and delivers it to the secondary rolling-die dand stationary die d. In passing through the secondary dies the shallowgroove upon the periphery of the blank one of the rolling-dies.

point on the end of the screw.

produced by the primary dies, which is represented approximately in Fig.5, is deepened, so that the central longitudinal section of the screwpresents an approximation to the appearance indicated in Fig. 6. V

In some cases Imayomit the transfer-wheel and substitute in its placethe secondary dies, delivering from the primary dies directly to thesecondary dies, which, except as to their size, would be represented bythe transferwheel 0 and the stationary guide-wall c.

In the case of large screws, especially woodscrews in which a deepthread isrequired, I may increase the number of pairs of dies in theseries, employing each successive pair of dies to deepen the groove madeby the next preceding pair of dies until the thread is finished to theproper depth.

I have shown in connection with my secondary dies a milling-wheel forcutting a cone- This millingwheel I, which is a well-known device, has,it will be seen, a beveled cutting-edge, and is affixed to a pulley, i,loosely mounted upon the hollow cylinder 1, through which the shaftDpasses, and is driven by the belt 01, which is carried by means ofleaders to the pulley i on the driving-shaft A of the machine.

The milling-wheel, which is driven at a higher speed than therolling-die d, rotates upon an axis which is parallel with, but slightlydis- .tant from, the axis of the die d, so that its work on the point ofthe screw will be progressively done, and also so that the edge of themillingwheel will not project beyond the periphery of the rolling-die atthe place where the blank is delivered to the rolling-die.

In certain cases where only a shallow thread is required, only one pairof my notched dies may be necessary, and in such a case, as indeed inall other cases, the primary rolling-die may be provided with amilling-wheel.

In the case of very large screws it may be desirable tb divide the workof cutting the conical point by providing milling-wheels for each Itwill be seen that the transfer-wheel c and its guide-wall 0 may beomitted and some other transfer device be substituted therefor. If,however, the transfer-wheel is employed, it

versely notched at intervals, substantially as i and for the purposedescribed. a

2. 1n machines for forming screw-threads, jointly, two or more pairs ofdies, each pair consisting of a rotating die and a stationary curveddie, the respective pairs of dies having the ridges on theirworking-faces relatively varying in depth or width, for the purpose offorming the thread of a screw or bolt by a series of two or moreprogressive operations, the primary dies forming a shallow spiral grooveupon the body of the blank,-and the subsequently following pair or pairsof dies succes sively deepening and enlarging such groove until thethread is finished,substantially as described.

3. The combination of pairs of dies, substantially such as described,with transferring mechanism for conveying the blanks from one pair ofdies to the next following pair of dies, consisting of the wheel 0 andthe guide a, substantially such as described.

4. The oscillating arm H, connected with the spring k and provided withthe tripper H, in combination with the stationaryguide H and with theactuating-pin H all arranged and operating substantially as and for thepurpose set forth. I

5. The hollow cylinder I, affording upon its exterior the bearing forthe milling-wheel I, in combination with the shaft D, extendingeccentrically through the hollow cylinder I, and carrying the rotatingdie d, substantially as shown and described.

H. A. HARVEY.

Witnesses M. L. ADAMS, Enwn. PAYSON.

